Systems and Methods for Multicast Resource Allocation

ABSTRACT

A method for a multicast service is provided. In this example, the method includes receiving, by a user equipment (UE), a control format including a resource allocation field from a base station (BS), the resource allocation field indicating a starting resource block (RB) index and an RB range, obtaining a set of RBs allocated for a multicast physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) based on a starting RB location and the RB range; wherein the starting RB location is associated with the stating RB index and at least one of a reference RB location or an assigned sub-band; and transmitting or receiving, by the UE, data over at least one RB of the set of RBs allocated for the multicast PDSCH or PUSCH.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 62/806,436, filed on Feb. 15, 2019, entitled “Systemsand Methods for Multicast Resource Allocation,” which is herebyincorporated by reference herein as if reproduced in its entirety.

TECHNICAL FIELD

The present invention relates to wireless communications, and, inparticular embodiments, to systems and methods for multicast resourceallocation.

BACKGROUND

Downlink control information (DCI) formats are communicated over aphysical downlink control channel (PDCCH) to notify user equipments(UEs) of physical downlink shared channel (PDSCH) or physical uplinkshared channel (PUSCH) resource grants. Techniques for reducing overheadwhen communicating PDSCH resource grants over the PDCCH are needed tosatisfy the performance requirements of long term evolution (LTE) andfifth generation (5G) new radio (NR) wireless standards.

In current 5G network system, there are two DCI formats for schedulingdata in DL and two DCI formats for scheduling data in UL. An example isDCI format 1_0, known as fallback DCI for DL. If it is monitored in acommon search space (CSS), the size of its frequency domain resourceassignment (FDRA) field is given by the size of CORESET 0 if CORESET 0is configured for the cell and the size of initial DL bandwidth part ifCORESET 0 is not configured for the cell. But DCI format 1_0 does notsupport BWP switching and cross-carrier scheduling, thus can be used forscheduling PDSCH in the active BWP. Another example is DCI format 0_0,known as fallback DCI for UL. If it is monitored in a common searchspace (CSS), the size of its FDRA field is given by the size of theinitial UL bandwidth part. But DCI format 0_0 does not support BWPswitching and cross-carrier scheduling. Another example is DCI format1_1, known as non-fallback DCI for DL. It is monitored in UE-specificsearch space and the size of FDRA field is given by the active DL BWP.DCI format 1_1 can support BWP switching and cross-carrier scheduling.Another example is DCI format 0_1, known as non-fallback DCI for UL. Itis monitored in UE-specific search space and the size of FDRA field isgiven by the active UL BWP. DCI format 0_1 can support BWP switching andcross-carrier scheduling. All the above 5G DCI formats do not supportmulticast scheduling with BWP switching or cross-carrier scheduling, andthus, a new DCI format design and resource allocation mechanism will beneeded.

SUMMARY OF THE INVENTION

Technical advantages are generally achieved by embodiments of thisdisclosure which describe systems and methods for multicast resourceallocation.

According to one aspect of the present disclosure, a method for amulticast service is provided, wherein the method includes receiving, bya user equipment (UE), a control format including a resource allocationfield from a base station, the resource allocation field indicating astarting resource block (RB) index and an RB range; obtaining a set ofRBs allocated for a multicast physical downlink shared channel (PDSCH)or physical uplink shared channel (PUSCH) based on a starting RBlocation and the RB range; wherein the starting RB location isassociated with the stating RB index and at least one of a reference RBlocation or an assigned sub-band; and transmitting or receiving, by theUE, data over at least one RB of the set of RBs allocated for themulticast PDSCH or PUSCH.

Optionally, in some embodiments of any of the preceding aspects, theobtaining the set of RBs of the multicast PDSCH or PUSCH comprises:locating a starting RB of the multicast PDSCH or PUSCH based on thestarting RB location and the reference RB location; and locating anending RB of the multicast PDSCH or PUSCH based on the RB range and thestarting RB of the multicast PDSCH or PUSCH.

Optionally, in some embodiments of any of the preceding aspects, theobtaining the set of RBs of the multicast PDSCH or PUSCH comprises:locating a starting RB of the multicast PDSCH or PUSCH based on thestarting RB location and a starting RB of the assigned sub-band; andlocating an ending RB of the multicast PDSCH or PUSCH based on the RBrange and the starting RB of the multicast PDSCH or PUSCH.

According to another aspect of the present disclosure, a method for amulticast service is provided, wherein the method includes sending, by abase station, a resource allocation field to a group of UEs, theresource allocation field indicating a starting resource block (RB)index and an RB range; and transmitting or receiving, by the basestation, data over at least one RB of a set of RBs in a multicast PDSCHor PUSCH with the group of UEs, wherein a set of RBs of the multicastPDSCH or PUSCH are identified based on a starting RB location and the RBrange, and the starting RB location is associated with the stating RBindex and at least one of a reference RB location or an assignedsub-band.

Optionally, in some embodiments of any of the preceding aspects, themethod further comprising: assigning, by the BS, a multicast groupidentity (ID) a first UE and a second UE of the group UEs, constructing,by the BS, a control format which includes the resource allocationfield, and a Cyclic Redundancy Check (CRC) based on the control format,and scrambling, by the BS, the CRC by the multicast group ID.

Optionally, in some embodiments of any of the preceding aspects, theresource allocation field is signaled based on at least one of: adownlink control information (DCI) for downlink multicast, wherein asize of the resource allocation field can determined in accordance withany one of a size of a common control resource set (CORESET), a size ofan initial downlink BWP, a size of a downlink BWP having a smallest BWPID among a plurality of downlink BWPs configured for a first UE and asecond UE; a size of a default downlink bandwidth part (BWP) configuredfor the first UE and the second UE; a numerology of a current activeBWP; or a downlink component carrier within which a control format istransmitted to the first UE and the second UE; a downlink controlinformation (DCI) for uplink multicast, wherein a size of the resourceallocation field is determined in accordance with a size of an uplinkbandwidth part (BWP), the uplink BWP having a smallest BWP ID among aplurality of uplink BWPs configured for the first UE; or a higher-layerparameter indicating a first plurality of reference RBs comprises the(k×N)-th common RB, k being an integer and N being a pre-determinedvalue.

Optionally, in some embodiments of any of the preceding aspects, thecommon CORESET is a CORESET with CORESET ID #0 within a carrier wherethe DCI is received.

Optionally, in some embodiments of any of the preceding aspects, thecontrol format is size-matched to a type 1_0 DCI.

Optionally, in some embodiments of any of the preceding aspects, N is amultiple of a configured RB group size or a configured RB bundle size;or N is determined in accordance with a numerology of an active downlinkbandwidth part (BWP).

Optionally, in some embodiments of any of the preceding aspects, thereference RB is assigned to the group UEs by a higher layer signaling,and the reference RB comprises a first plurality of reference RBscomprises a set of common RBs, the set of common RBs are configured byhigher layers.

Optionally, in some embodiments of any of the preceding aspects, beforethe sending the method further comprising: sending, by the BS, a BWPidentifier (ID) indicating a first BWP to a first UE and a second BWP toa second UE, and wherein the at least one RB belongs to one of the firstBWP and the second BWP.

Optionally, in some embodiments of any of the preceding aspects, thefirst BWP is different from the second BWP in a same carrier or anaggregation of carriers.

Optionally, in some embodiments of any of the preceding aspects, the atleast one RB belonging to the one of the first BWP and the second BWPhas a lowest RB index among a first subset of the first plurality ofreference RBs, the first subset of the first plurality of reference RBsbelonging to the first BWP.

Optionally, in some embodiments of any of the preceding aspects, the setof RBs has a size of one of: an initial downlink bandwidth part (BWP) oran initial uplink BWP configured for a first component carrier; adownlink BWP or an uplink BWP, the downlink BWP or uplink BWP having asmallest BWP ID among a plurality of downlink BWPs or uplink BWPsconfigured for a first UE within a component carrier; a default downlinkbandwidth part (BWP) or a default uplink BWP configured for the firstcomponent carrier; or a size in accordance with which a size of theresource allocation field is determined or configured using DCI or ahigher layer signaling message.

Optionally, in some embodiments of any of the preceding aspects, theresource allocation field includes a bitmap indicating the at least oneRB to be used for the multicast service.

Optionally, in some embodiments of any of the preceding aspects, the atleast one RB includes a set of contiguously allocated RBs, and whereinthe resource allocation field includes a resource indication value (RIV)corresponding to a starting RB and a length of the set of contiguouslyallocated RBs.

Optionally, in some embodiments of any of the preceding aspects, thestarting RB and the length of the set of contiguously allocated RBs aredetermined in accordance with the RIV and a scale factor if M isdifferent than N, M being a size of a number of contiguous RBs, N beingsize in accordance with which a size of the resource allocation field isdetermined.

According to another aspect of the present disclosure, a device isprovided, wherein the device includes: a non-transitory memory storagecomprising instructions; and one or more processors in communicationwith the non-transitory memory storage, wherein the one or moreprocessors execute the instructions to: receive a control formatincluding a resource allocation field from a base station, the resourceallocation field indicating a starting resource block (RB) index and anRB range; obtain a set of RBs allocated for a multicast physicaldownlink shared channel (PDSCH) or physical uplink shared channel(PUSCH) based on a starting RB location and the RB range; wherein thestarting RB location is associated with the stating RB index and atleast one of a reference RB location or an assigned sub-band; andtransmit or receive data over at least one RB of the set of RBsallocated for the multicast PDSCH or PUSCH.

Optionally, in some embodiments of any of the preceding aspects, theinstructions to obtain the set of RBs comprise instructions to: locate astarting RB of the multicast PDSCH or PUSCH based on the starting RBlocation and the reference RB location; and locate an ending RB of themulticast PDSCH or PUSCH based on the RB range and the starting RB ofthe multicast PDSCH or PUSCH.

Optionally, in some embodiments of any of the preceding aspects, theinstructions to obtain the set of RBs comprise instructions to: locate astarting RB of the multicast PDSCH or PUSCH based on the starting RBlocation and a starting RB of the assigned sub-band; and locate anending RB of the multicast PDSCH or PUSCH based on the RB range and thestarting RB of the multicast PDSCH or PUSCH.

According to another aspect of the present disclosure, a device isprovided, wherein the device includes: a non-transitory memory storagecomprising instructions; and one or more processors in communicationwith the non-transitory memory storage, wherein the one or moreprocessors execute the instructions to: send a resource allocation fieldto a group of UEs, the resource allocation field indicating a startingresource block (RB) index and an RB range; and transmit or receive dataover at least one RB of a set of RBs in a multicast PDSCH or PUSCH withthe group of UEs, wherein a set of RBs of the multicast PDSCH or PUSCHare identified based on a starting RB location and the RB range, and thestarting RB location is associated with the stating RB index and atleast one of a reference RB location or an assigned sub-band.

Optionally, in some embodiments of any of the preceding aspects, the oneor more processors execute further instructions to: assign a multicastgroup identity (ID) a first UE and a second UE of the group UEs, andreceive a Cyclic Redundancy Check (CRC) data scrambled by the multicastgroup ID is attached to a control format from the first UE and thesecond UE.

Optionally, in some embodiments of any of the preceding aspects, theresource allocation field is signaling based on at least one of: adownlink control information (DCI) for downlink multicast; and a size ofthe resource allocation field can determined in accordance with any oneof a size of a common control resource set (CORESET), a size of aninitial downlink BWP, a size of a downlink BWP having a smallest BWP IDamong a plurality of downlink BWPs configured for a first UE and asecond UE; a size of a default downlink bandwidth part (BWP) configuredfor the first UE and the second UE; a numerology of a current activeBWP; or a downlink component carrier within which a control format istransmitted to the first UE and the second UE; a downlink controlinformation (DCI) for uplink multicast, and wherein a size of theresource allocation field is determined in accordance with a size of anuplink bandwidth part (BWP), the uplink BWP having a smallest BWP IDamong a plurality of uplink BWPs configured for the first UE; or ahigher-layer parameter indicating a first plurality of reference RBscomprises the (k×N)-th common RB, k being an integer and N being apre-determined value.

Optionally, in some embodiments of any of the preceding aspects, thecommon CORESET is a CORESET with CORESET ID #0 within a carrier wherethe DCI is received.

Optionally, in some embodiments of any of the preceding aspects, thecontrol format is size-matched to a type 1_0 DCI.

Optionally, in some embodiments of any of the preceding aspects, N is amultiple of a configured RB group size or a configured RB bundle size;or N is determined in accordance with a numerology of an active downlinkbandwidth part (BWP).

Optionally, in some embodiments of any of the preceding aspects, thereference RB is assigned to the group UEs by a higher layer signaling,and the reference RB comprises a first plurality of reference RBscomprises a set of common RBs, the set of common RBs are configured byhigher layers.

Optionally, in some embodiments of any of the preceding aspects, the oneor more processors execute further instructions to send a first BWPidentifier (ID) indicating a first BWP to a first UE, and a second BWPID indicating a second BWP to a second UE prior to sending the resourceallocation field, and wherein the at least one RB belongs to one of thefirst BWP and the second BWP.

Optionally, in some embodiments of any of the preceding aspects, thefirst BWP is different from the second BWP in a same carrier or anaggregation of carriers.

Optionally, in some embodiments of any of the preceding aspects, the atleast one RB belonging to the one of the first BWP and the second BWPhas a lowest RB index among a first subset of the first plurality ofreference RBs, the first subset of the first plurality of reference RBsbelonging to the first BWP.

Optionally, in some embodiments of any of the preceding aspects, the setof RBs has a size of one of: an initial downlink bandwidth part (BWP) oran initial uplink BWP configured for a first component carrier; adownlink BWP or an uplink BWP, the downlink BWP or uplink BWP having asmallest BWP ID among a plurality of downlink BWPs or uplink BWPsconfigured for a first UE within a component carrier; a default downlinkbandwidth part (BWP) or a default uplink BWP configured for the firstcomponent carrier; or a size in accordance with which a size of theresource allocation field is determined or configured using DCI or ahigher layer signaling message.

Optionally, in some embodiments of any of the preceding aspects, theresource allocation field includes a bitmap indicating the at least oneRB to be used for the multicast service.

Optionally, in some embodiments of any of the preceding aspects, the atleast one RB includes a set of contiguously allocated RBs, and whereinthe resource allocation field includes a resource indication value (RIV)corresponding to a starting RB and a length of the set of contiguouslyallocated RBs.

Optionally, in some embodiments of any of the preceding aspects, thestarting RB and the length of the set of contiguously allocated RBs aredetermined in accordance with the RIV and a scale factor if M isdifferent than N, M being a size of a number of contiguous RBs, N beingsize in accordance with which a size of the resource allocation field isdetermined.

According to another aspect of the present disclosure, a device isprovided, wherein the device includes: a non-transitory memory storagecomprising instructions; and one or more processors in communicationwith the non-transitory memory storage, wherein the one or moreprocessors execute the instructions to: receive a resource configurationfield identifying a multicast bandwidth part (BWP) from a base station,the resource configuration field excluding a BWP ID of the multicastbandwidth part BWP; and transmit or receive multicast data over at leastone resource block (RB) of the multicast bandwidth part BWP.

According to another aspect of the present disclosure, a device isprovided, wherein the device includes: a non-transitory memory storagecomprising instructions; and one or more processors in communicationwith the non-transitory memory storage, wherein the one or moreprocessors execute the instructions to: transmit a resourceconfiguration field identifying a multicast bandwidth part (BWP) to twoor more user equipments (UEs), the resource configuration fieldexcluding a BWP ID of the multicast bandwidth part (BWP); and transmitor receive multicast data over at least one resource block (RB) of themulticast bandwidth part BWP to or from the two or more UEs.

According to another aspect of the present disclosure, a device isprovided, wherein the device includes: a non-transitory memory storagecomprising instructions; and one or more processors in communicationwith the non-transitory memory storage, wherein the one or moreprocessors execute the instructions to: receive a downlink controlinformation (DCI) identifying a multicast bandwidth part (BWP) from abase station (BS), the DCI excluding a BWP ID of the multicast bandwidthpart BWP; and transmit or receive multicast data over at least oneresource block (RB) of the multicast BWP.

According to another aspect of the present disclosure, a device isprovided, wherein the device includes: a non-transitory memory storagecomprising instructions; and one or more processors in communicationwith the non-transitory memory storage, wherein the one or moreprocessors execute the instructions to: transmit a downlink controlinformation (DCI) identifying a multicast bandwidth part (BWP) to two ormore user equipments (UEs), the DCI excluding a BWP ID of the multicastbandwidth part (BWP); and transmit or receive multicast data over atleast one resource block (RB) of the multicast BWP to or from the two ormore UEs.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram of an embodiment wireless network;

FIGS. 2A-2B are diagrams of multicast transmissions;

FIGS. 3A-3D are diagrams of embodiment multicast resource allocationschemes for signaling multicast resource allocation fields;

FIGS. 4A-4D are diagrams of additional embodiment multicast resourceallocation schemes for signaling multicast resource allocation fields;

FIG. 5 is a flowchart of a method for multicast service;

FIG. 6 is a flowchart of another method for multicast service;

FIG. 7 is a diagram of an embodiment multicast resource allocationscheme for signaling multicast resource allocation fields;

FIG. 8 is a flowchart of a method for multicast service;

FIG. 9 is a flowchart of another method for multicast service;

FIG. 10 is a block diagram of an embodiment processing system; and

FIG. 11 illustrates a block diagram of a transceiver.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of embodiments of this disclosure are discussed indetail below. It should be appreciated, however, that the presentinvention provides many applicable inventive concepts that can beembodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention. Itshould be appreciated that much of this disclosure describes theinventive aspects of multicast resource allocation within the context oftwo UEs, but that the disclosed inventive aspects are not so limited,and can easily be extended to groups of three or more UEs.

A multicast DL transmission refers to a scenario where a BS aims totransmit the same data (multicast DL data) to UEs within a group of UEs.In such scenario, the BS transmits a single physical downlink controlchannel (PDCCH) containing a DCI to schedule a single physical downlinkshared channel (PDSCH) containing the multicast data for all the UEswithin the group of UEs, and each UE within the group of UEs receivesthe same DCI and then receives the same multicast DL data within thesame PDSCH scheduled by the DCI. A multicast UL transmission refers to ascenario where a BS schedules each UE within a group of UEs to transmitdata (which is potentially different from the data of other UEs withinthe group of UEs) in physical uplink shared channel (PUSCH) over thesame set of UL resources. In particular, the BS transmits a single PDCCHcontaining a DCI to schedule the same set of UL resources to each UEwithin the group of UEs, and each UE within the group of UEs receivesthe same DCI and transmits its own UL data over the same UL resourcesscheduled by the DCI.

The current scheduling DCI formats in 5G has the followingissues/limitations: DCI format 1_0 for DL (or format 0_0 for UL) doesnot support BWP switching and cross-carrier scheduling. For DCI format1_1 for DL (or format 0_1 for UL) can support BWP switching andcross-carrier scheduling, however the size of FDRA field of the DCI isbased on the size of the active (DL or UL) BWP. Therefore, In order touse DCI format 1_1 or DCI format 0_1 in multicast scenario, the size ofthe active BWP of each UE in the group of UEs should be the same, whichis an undesired limitation in BWP configuration. The invention of thisdisclosure provides a first solution how to allocate resources formulticast PDSCH or multicast PUSCH to a group of UEs with differentactive BWPs and different scheduled BWPs, and a second solution how toallocate resources for multicast PDSCH or multicast PUSCH incarrier-aggregation (specially in cross-carrier scheduling). The generalconcept of the two solutions is to send a multicast DCI to a group ofUEs, the multicast DCI indicating a same size of the scheduled PDSCH orPUSCH within the scheduled BWP (i.e. the BWP whose ID is indicated inthe DCI) for each UE in the group, for an example, the starting RB ofthe scheduled PDSCH or PUSCH in the scheduled BWP should be the same forall UEs in the group, and thus, achieve multicast transmission.

Aspects of this disclosure provide an efficient mechanism for signalingmulticast resource grants to allow user equipments (UEs) to identify theresource blocks of multicast PDSCH (or multicast PUSCH for UL) allocatedfor multicast data transmissions based on a combination of the existingDCI formats (No new DCI format) with a new RNTI. For an example, use oneof the current non-fallback DCI formats, i.e. DCI 1_1 for DL and 0_1 forUL, together with a new RNTI for multicast (e.g. MC-RNTI), and the RBnumbering and RB range details disclosed in some of the followingembodiments.

Other aspects of this disclosure provide an efficient mechanism forsignaling multicast resource grants to allow UEs to identify theresource blocks of multicast PDSCH (or multicast PUSCH for UL) allocatedfor multicast data transmissions based on a new DCI format for multicast(i.e. a new DCI format which supports multicast scheduling in any BWP),or a combination of the new DCI format and a new RNTI (with possiblesize-matching of the new DCI format to DCI 0_0/1_0), and the RBnumbering and RB range details disclosed in some of the followingembodiments.

In particular, a base station transmits a resource allocation field(also known as frequency domain resource assignment (FDRA) field) to agroup of UEs that indicates a set of RBs allocated for multicasttransmission. In any of the embodiments described in this disclosure,the RBs indicated by the resource allocation field may be either virtualresource blocks (VRBs) or physical resource blocks (PRBs). Also, theterms resource allocation field and frequency domain resource assignment(FDRA) field are interchangeably used throughout this disclosure. Thevalue of the resource allocation field is used by each UE within thegroup of UEs to locate the set of RBs allocated for the multicast PDSCHor PUSCH based on at least one of a reference RB location, a referencesub-band, or a multicast bandwidth part (BWP). A multicast BWP may bereferred to as a group-common BWP, and both terms are usedinterchangeably in this disclosure. In one example, resource allocationfield indicates a starting RB and an RB range. In one example, resourceallocation type 1 may be used for multicast resource allocation, whereinthe resource allocation field indicates a resource indication value(RIV) which implicitly indicates a starting RB and an RB range. Thestarting RB indicated by the resource allocation field is used by theUEs to locate the starting RB of a set of contiguous RBs allocated forthe multicast PDSCH or PUSCH based on at least one of a reference RBlocation, a reference sub-band, or a multicast BWP, and the RB rangeindicated by the resource allocation field is used by the UEs toidentify the ending RB of the set of contiguous RBs allocated for themulticast PDSCH based on the starting RB location. In another example,resource allocation type 0 may be used for multicast resourceallocation, wherein the resource allocation field indicates a set ofresource block groups (RBGs) using a bitmap wherein the RBs belonging toRBGs corresponding to bit values equal to 1 are allocated for multicasttransmission. The bitmap indicated by the resource allocation field isused by the UEs to locate the RBGs of the multicast PDSCH or PUSCH basedon at least one of a reference RB location, a reference sub-band, or amulticast BWP. The multicast PDSCH (or PUSCH for UL) may include acommon set of RBs with respective bandwidth parts (BWPs) that arescheduled to the UEs. It should be appreciated that BWPs scheduled todifferent UEs and used for multicast transmission at least partiallyoverlap with one another in the frequency domain, and that the commonset of RBs map to frequency domain resources in the overlapping portionsof the BWPs. It should further be appreciated that the respective BWPsmay be located on the same component carrier or serving cell or ondifferent component carriers or different serving cells. It should benoted that the terms “component carrier”, “carrier”, and “serving cell”are interchangeably used in this disclosure.

FIG. 1 is a diagram of a wireless network 100 for communicating data.The wireless network 100 includes a base station no having a coveragearea 101, a plurality of mobile devices 120, and a backhaul network 130.As shown, the base station 110 establishes uplink (dashed line) and/ordownlink (dotted line) connections with the user equipments (UEs) 122,124, which serve to carry data from the UEs 122, 124 to the base stationno and vice-versa. Data carried over the uplink/downlink connections mayinclude data communicated between the UEs 120, as well as datacommunicated to/from a remote-end (not shown) by way of the backhaulnetwork 130. As used herein, the term “base station” refers to anycomponent (or collection of components) configured to provide wirelessaccess to a network, such as an evolved NodeB (eNB), a generalized NodeB(gNB), a macro-cell, a femtocell, a Wi-Fi access point (AP), or otherwirelessly enabled devices. Base stations may provide wireless access inaccordance with one or more wireless communication protocols, e.g., newradio (NR), long term evolution (LTE), LTE advanced (LTE-A), High SpeedPacket Access (HSPA), Wi-Fi 802.11a/b/g/n/ac. As used herein, the term“UE” refers to any component (or collection of components) capable ofestablishing a wireless connection with a base station. The terms “UE,”“mobile device,” and “mobile station (STA)” are used interchangeablythroughout this disclosure. In some embodiments, the network 100 maycomprise various other wireless devices, such as relay stations,schedulers, central controllers, and the like.

In some embodiments, multicast transmissions may be exchanged betweenbase stations and UEs in a wireless network. Multicast transmissions mayinclude downlink multicast transmissions communicated from a basestation to UEs in a group of UEs configured for multicast reception.FIG. 2A is a diagram 201 of a multicast downlink transmission 291 from abase station 210 to UEs 222, 224, 228 in a group of UEs 220. Componentcarrier group 230 includes DL component carriers 232, 234, and 238. Inthis example, the multicast downlink transmission 291 is communicatedover DL component carriers 232, 234, 238, with the UE 222 receiving themulticast downlink transmission 291 over the component carrier 232, theUE 224 receiving the multicast downlink transmission 291 over thecomponent carrier 234, and the UE 228 receiving the multicast downlinktransmission 291 over the component carrier 238. The component carriers232, 234, 238 may be orthogonal or non-orthogonal in the frequencydomain. In other examples, multicast downlink transmissions may becommunicated to two or more UEs over the same DL component carrier. Herea component carrier refers to the primary carrier accessed by a UE, orany of the primary carrier or secondary carriers configured to a UE inthe case of carrier aggregation.

Multicast transmissions may also include uplink multicast transmissionscommunicated to a base station from UEs in a group of UEs configured formulticast transmission. FIG. 2B illustrates a diagram 202 of a multicastuplink transmission 291 from the UEs 222, 224, 228 to the base station210. Similar to the multicast downlink transmission 291, the multicastuplink transmission 292 is communicated over UL component carriers 242,244, 248, with the UE 222 transmitting the multicast uplink transmission292 over the component carrier 242, the UE 224 transmitting themulticast downlink transmission 292 over the component carrier 244, andthe UE 228 transmitting the multicast downlink transmission 292 over thecomponent carrier 248. Component carrier group 240 includes UL componentcarriers 242, 244, and 248. The component carriers 242, 244, 248 may beorthogonal or non-orthogonal in the frequency domain. In other examples,multicast downlink transmissions may be communicated to two or more UEsover the same UL component carrier.

A multicast UL transmission refers to a scenario where a BS scheduleseach UE within a group of UEs to transmit data (which is potentiallydifferent from the data of other UEs within the group of UEs) inphysical uplink shared channel (PUSCH) over the same set of ULresources. In particular, the BS transmits a single PDCCH containing aDCI to schedule one set of UL resources to each UE within the group ofUEs, and each UE within the group of UEs receives the same DCI andtransmits its own UL data over the same UL resources scheduled by theDCI.

It should be appreciated that any number of UEs may be included in thegroup of UEs 220, and that any number of component carriers may beincluded in the groups of component carriers 230 and 240. It should alsobe appreciated that, in some embodiments, two or more UEs may transmitand/or receive the multicast uplink transmission 292 and/or themulticast downlink transmission 291 over the same component carrier.Other examples are also possible. For instance, the same UE may transmitand/or receive a multicast transmission over different componentcarriers to provide redundancy in order to achieve improved reliability.

Multicast transmissions may be communicated over portions of bandwidthparts (BWPs) that are assigned for multicast PDSCH (or PUSCH for UL).Aspects of this disclosure signal a resource allocation field in a DCImessage to notify UEs of the RBs allocated to the multicast PDSCH orPUSCH.

In some embodiments, the resource allocation field may be used toidentify the RBs allocated for a multicast PDSCH/PUSCH based on areference RB or a combination of a reference RB and a reference size. Insome embodiments, RB numbering for multicast resource allocation startsfrom the reference RB.

The resource allocation field may be included in a downlink controlinformation (DCI) message, which is also called multicast DCI in thisdisclosure. A multicast DCI message is constructed based on a DCI formatwhich describes bitfields of the multicast DCI message. A multicast DCImessage is transmitted to a group of UEs in a physical downlink controlchannel (PDCCH). Transmission of a multicast DCI message in a PDCCH mayinvolve other step, including appending of cyclic redundancy check (CRC)bits to the multicast DCI message, scrambling of the a radio networktemporary identifier (RNTI), and encoding of the resulting bits using aforward error correction (FEC) encoder. In one embodiment, a specificDCI format is used for scheduling multicast PDSCH (also called DLmulticast DCI) and/or a specific DCI format is used for schedulingmulticast PUSCH (also called UL multicast DCI). In another embodiment,the same DCI format which is used for scheduling other types of PDSCH(or PUSCH) can be used for scheduling multicast PDSCH (or PUSCH). Insome embodiments, DL fallback DCI may be used as DL multicast DCI and/orUL fallback DCI may be used as UL multicast DCI. In some embodiments,the DCI 1_0 is used as DL fallback DCI and/or DCI 0_0 is used asfallback UL DCI. In some embodiments, DCI 1_0 may be used as DLmulticast PDSCH and/or DCI 0_0 may be used as UL multicast PUSCH.

In some embodiments, a size of the resource allocation field isdetermined based on frequency size of a common control resource set(CORESET) in a scheduling cell or scheduling carrier. A scheduling cellis a serving cell where the UE receives the PDCCH containing themulticast DCI. The PDCCH containing the multicast DCI may be received inan active BWP of the scheduling cell of each UE within a group of UEsfor multicast communication. In some embodiments, different UEs withinthe group of UEs may have different active BWPs and/or differentscheduling cells, but they all receive the same PDCCH containing thesame multicast DCI message. In some embodiments, the size of theresource allocation field is determined based on frequency size of theCORESET where the multicast DCI message is received by the UE. In someembodiments, the size of the resource allocation field is determinedbased on frequency size of the CORESET with CORESET ID #0 in thescheduling cell. In some embodiments, the size of the resourceallocation field is determined based on the size of an initial DL BWP orthe size of an initial UL BWP of the scheduling cell. In someembodiments, the size of the resource allocation field is determinedbased on the size of DL BWP (or UL BWP) configured in the scheduledserving cell which has the smallest BWP ID or largest BWP ID among theDL BWPs (or UL BWPs) configured in the scheduling cell for a UE. In someembodiments, the size of the resource allocation field is determinedbased on the size of the default DL BWP (or UL BWP) in the schedulingcell. In some embodiments, the size of the resource allocation field iseither a fixed number or a predefined number or a number configured byhigher layers. In embodiments where the size of the resource allocationfield is configured by higher layers, the size of the resourceallocation field can be configured per scheduling cell, or perconfigured numerology of the scheduling cell, or per configured BWP ofthe scheduling cell. In embodiments where a UE locates the RBs allocatedfor multicast transmission based on a reference RB and reference size,in some examples, the size of the resource allocation field isdetermined based on the reference size. In embodiments where a UElocates the RBs allocated for multicast transmission based on areference sub-band, in some examples, the size of the resourceallocation field is determined based on the sub-band size. Inembodiments where a UE locates the RBs allocated for multicasttransmission based on a multicast or group-common BWP, in some examples,the size of the resource allocation field is determined based on thesize of the multicast or group-common BWP.

Denote by A the size of the resource allocation field and by N_(size)the size based on which the size of the resource allocation field (A) isdetermined (for examples, N_(size) is any of the sizes described in theembodiments above). In some embodiments, when only resource allocationtype 1 is configured for multicast PDSCH or PUSCH, the size of theresource allocation field is equal to A=┌log₂(N_(size)(N_(size)+1)/2)┐bits. In some embodiments, when only resource allocation type 0 isconfigured for multicast PDSCH or PUSCH, the size of the resourceallocation field is equal to A=┌(N_(size) (N_(start) mod P))/P┐ bits,where P is the RBG size and N_(start) is the common resource block (CRB)index of the RB where the RB numbering for resource allocation startsfrom according to any of the embodiments described in this disclosure.In an example, N_(start) is the CRB index of a reference RB used formulticast PDSCH or PUSCH. In another example, N_(start) is the CRB indexof the lowest RB of a sub-band used for the multicast PDSCH or PUSCH. Inyet another example, N_(start) is the CRB index of the starting RB of amulticast BWP or group-common BWP used for the multicast PDSCH or PUSCH.In some embodiments, when both resource allocation type 0 and resourceallocation type 1 are configured for multicast PDSCH or PUSCH, the sizeof the resource allocation field is equal toA=max(┌log₂(N_(size)(N_(size) 1)/2)┐, ┌(N_(size)+(N_(start)mod P))/P┌)bits.

In some embodiments, a multicast DCI includes a BWP ID field to indicatethe BWP ID of the scheduled BWP, i.e. a DL BWP which contains theallocated RBs for a multicast PDSCH or an UL BWP which contains theallocated RBs for a multicast PUSCH. In some embodiments, a multicastDCI includes a carrier ID field (CIF) to indicate the scheduled cell orscheduled carrier, i.e. the serving cell or component carrier i.e. a DLcarrier which contains the allocated RBs for a multicast PDSCH or an ULcarrier which contains the allocated RBs for a multicast PUSCH. In someembodiments, where a CIF is included in the multicast DCI, the scheduledBWP belongs to the scheduled cell.

In some embodiments, an UL multicast DCI may be size-matched to a DLmulticast DCI. In some embodiments, a DL multicast DCI is size-matchedto an UL multicast DCI. In some embodiments, a DL multicast DCI issize-matched to an UL multicast DCI if a size of the DL multicast DCI(before size-matching) is smaller than a size of the UL multicast DCI,and/or an UL multicast DCI is size-matched to a DL multicast DCI if asize of the UL multicast DCI (before size-matching) is smaller than asize of the DL multicast DCI. In some embodiments, a DL multicast DCIand/or an UL multicast DCI is size-matched to DCI format 1_0 or 0_0. Thesize-matching of a first DCI format to second DCI format may be done bytruncating a number of most significant bits (MSBs) of the first DCIformat or a number of MSBs of a particular bitfield (e.g. a resourceallocation field) of the first DCI format so that the resulting size isequal to a size of the second DCI format. Alternatively, size-matchingof a first DCI format to second DCI format may be done by appending anumber of zero bits to MSBs of the first DCI format or to MSBs of aparticular bitfield (e.g. a resource allocation field) of the first DCIformat so that the resulting size is equal to a size of the second DCIformat.

In some embodiment, a specific RNTI for multicast communication, e.g. amulticast RNTI or MC-RNTI, may be used to scramble and/or descramblecyclic redundancy check (CRC) of the multicast DCI message and/or todetect the multicast DCI message. Advantageously, because a singleresource allocation field is communicated to a group of UEs, themulticast resource allocations are signaled using less overhead thanwould otherwise be used if resource allocations were signaledseparately.

FIGS. 3A-3D are diagrams of multicast resource allocation schemes301-304 for signaling multicast resource allocations to UEs 222, 224. Inthis example, a BWP 332 is assigned or scheduled to UE 222 and a BWP 334is assigned or scheduled to UE 224. The BWPs 332, 334 may be on the samecomponent carrier (or serving cell) or on different component carriers(or serving cells). As shown, the BWP 332 at least partially overlapswith the BWP 334 in the frequency domain such that a common sequence ofcontiguous RBs (RB₀, RB₂, . . . , RB₈) belong to both of the BWPs 332,334.

In each of the multicast resource allocation schemes 301-304, the basestation 210 sends a resource allocation field 381-384 to the UEs 222,224. The resource allocation fields 381-383 indicate a starting RB indexand an RB range (implicitly using RIV or explicitly), which are used toidentify a set of contiguous RBs allocated for the multicastPDSCH/PUSCH. In some embodiments, the set of contiguous RBs is a set ofcontiguous VRBs, wherein the starting RB is a starting VRB and the RBrange is a VRB range. The resource allocation field 384 indicates a setof RBGs, which are used to identify the RBs allocated for the multicastPDSCH/PUSCH.

The starting RB index indicated by (or derived from the RIV indicatedby) the respective resource allocation fields 381-383 is used toidentify the starting RB of a set of contiguous RBs allocated for themulticast PDSCH/PUSCH based on the reference RB location 390. The RBrange indicated by (or derived from the RIV indicated by) the respectiveresource allocation fields 381-383 is then used to identify the endingRB of the set of contiguous RBs allocated for the multicast PDSCH/PUSCHbased on the identified starting RB of the multicast PDSCH/PUSCH. Insome embodiments, the set of contiguous RBs is a set of contiguous VRBs,wherein the starting RB is a starting VRB and the RB range is a VRBrange. The RBGs indicated by the resource allocation field 384 are usedto identify the RBs allocated for the multicast PDSCH/PUSCH based on thereference RB location 390.

In particular, the resource allocation field 381 indicates (implicitlyusing RIV or explicitly) a starting RB index of one (starting_RB=1) andan RB range of four (RB_range=4). Upon receiving the resource allocationfield 381, the UEs 222, 224 identify the RB 391 (i.e., RB₁) as thestarting RB of a set of contiguous RBs allocated for the multicastPDSCH/PUSCH because the RB 391 is located one RB from the reference RB390. The UEs 222, 224 then identify the RB 394 (i.e., RB₄) as the endingRB of the set of contiguous RBs allocated for the multicast PDSCH/PUSCHbecause the RB 394 is located four RBs from the starting RB of the setof contiguous RBs allocated for the multicast PDSCH/PUSCH (i.e., fourRBs from the RB 391). In some embodiments, the set of contiguous RBs isa set of contiguous VRBs, wherein the starting RB is a starting VRB andthe RB range is a VRB range.

Taking FIG. 3B as a reference, the resource allocation field 382indicates (implicitly using RIV or explicitly) a starting RB index ofthree (starting_RB=3) and an RB range of six (RB_range=six). Uponreceiving the resource allocation field 382, the UEs 222, 224 identifythe RB 393 (i.e., RB₃) as the starting RB of a set of contiguous RBsallocated for the multicast PDSCH/PUSCH because the RB 393 is locatedthree RBs from the reference RB 390. The UEs 222, 224 then identify theRB 398 (i.e., RB₈) as the ending RB of the set of contiguous RBsallocated for the multicast PDSCH/PUSCH because the RB 398 is locatedsix RBs from the starting RB of the set of contiguous RBs allocated forthe multicast PDSCH/PUSCH (i.e., six RBs from the RB 393). In someembodiments, the set of contiguous RBs is a set of contiguous VRBs,wherein the starting RB is a starting VRB and the RB range is a VRBrange.

Taking FIG. 3C as a reference, the resource allocation field 383indicates (implicitly using RIV or explicitly) a starting RB index ofzero (starting_RB=0) and an RB range of seven (RB_range=seven). Uponreceiving the resource allocation field 383, the UEs 222, 224 identifythe RB 390 (i.e., RB₀) as the starting RB of a set of contiguous RBsallocated for the multicast PDSCH/PUSCH because, when the starting RB isequal to zero, the reference RB is the starting RB. The UEs 222, 224then identify the RB 396 (i.e., RB₆) as the ending RB of the set ofcontiguous RBs allocated for the multicast PDSCH/PUSCH because the RB396 is located seven RBs from the starting RB of the set of contiguousRBs allocated for the multicast PDSCH/PUSCH (i.e., seven RBs from the RB390). In some embodiments, the set of contiguous RBs is a set ofcontiguous VRBs, wherein the starting RB is a starting VRB and the RBrange is a VRB range.

Taking FIG. 3D as a reference, the resource allocation field 384indicates a bitmap of RBGs. In this specific example, the RBG size isequal to 2, i.e. each RBG (except for the first RBG) consists of 2 RBs.The first RBG includes reference RB 390. The second RBG includes RBs 391and 392. The third RBG includes RBs 393 and 394. The fourth RBG includesRBs 395 and 396. The fifth RBG includes RBs 397 and 398. It should beappreciated that the RBG size can be any other integer value P. In someembodiments, the RBG size can be a power of 2. In some embodiments, theRBG size may be a fixed value, or a predefined value, or a valueconfigured by higher layers, e.g. as part of BWP configuration. Uponreceiving the resource allocation field 384, the UEs 222, 224 identifythe RBs 391, 392, 395, 396 (i.e., RB₁, RB₂, RB₅, RB₆) as RBs allocatedfor the multicast PDSCH or PUSCH because, the resource allocation field384 is bitmap (01010) indicating that the second RBG and the fourth RBGare allocated. It should be noted that the first RBG (which includes thereference RB) and/or the last RBG may have a partial size, i.e. they mayconsist of less than P RBs. This is because RBG boundaries may or maynot be aligned with the reference RB.

In some embodiments, any of the above resource allocation fields 381 to383 can comprise a starting RB and an ending RB to identify a set ofRBs. Or other equivalent solutions. The reference RB can be identifiedby a physical resource block (PRB) index or a common resource block(CRB) index. The reference RB may be a priori information, for anexample, predefined to a UE or the group of UEs for multicastcommunication. In one embodiment, the reference RB is configured usinghigher layer signaling, e.g. as part of BWP configuration. In anotherembodiment, the reference RB may be selected from a set of multicastreference RBs. In one embodiment, the reference RB is the lowestreference RB within the set of multicast reference RBs which belongs tothe scheduled BWP. In one embodiment, the reference RB from the set ofmulticast reference RBs is signaled to a UE via a higher layer signalinge.g., a radio resource communications (RRC) signaling, or via a MAC CEsignaling or via a DCI message, or a combination thereof. In someembodiments, a subset of the set of multicast reference RBs is firstactivated using MAC CE or higher layer signaling and a DCI message isused to indicate the reference RB within the activated subset of the setof multicast reference RBs. The DCI message used to indicate thereference RB may be the same DCI massage that is used for scheduling themulticast PDSCH/PUSCH, in which case a separate DCI bitfield in the DCImessage may be used for such indication.

In some embodiments, the set of multicast reference RBs consists eitherof a fixed or predefined set of PRBs or CRBs, or a set of PRBs or CRBsconfigured by higher layers. In some embodiments, the set of multicastreference RBs consists of CRBs with CRB index k×N, k=0, 1, . . . ,within a component carrier, where N can be either of a fixed integer ora predefined integer or an integer configured by higher layers. Inembodiments where N is configured by higher layers, N can be configuredper serving cell, or per configured numerology of a serving cell, perconfigured BWP of a serving cell. In some embodiments, N may depend onother higher layer parameters configured to a UE. As an example, N isthe RBG size or a fixed integer multiple of the RBG size or ahigher-layer configurable integer multiple of the RBG size configuredfor the scheduled BWP (i.e. the BWP in which the multicast PDSCH/PUSCHis allocated to be transmitted). As another example, N is the RB bundlesize or a fixed integer multiple of the RB bundle size or a higher-layerconfigurable integer multiple of the RB bundle size configured for thescheduled BWP. As yet another example, for resource allocation type 0, Nis the RBG size or a fixed integer multiple of the RBG size or ahigher-layer configurable integer multiple of the RBG size configuredfor the scheduled BWP, and for resource allocation type 1, N is the RBbundle size or a fixed integer multiple of the RB bundle size or ahigher-layer configurable integer multiple of the RB bundle sizeconfigured for the scheduled BWP.

In some embodiments, a reference size is associated to multicastPDSCH/PUSCH. The reference size may either be a priori information to aUE or a group of UEs for multicast communication or otherwisecommunicated via higher layer signaling, e.g., RRC signaling, or via MACCE signaling, or via a DCI message, or a combination thereof. The DCImessage that is used for indication of the reference size may be thesame DCI massage that is used for scheduling the multicast PDSCH/PUSCH.In some embodiments, the reference size is equal to size N_(size) thatis used to determine the size of the multicast resource allocationfield. In some embodiments, the reference size is either a fixed numberor a predefined number or a number configured by higher layers. Inembodiments where the reference size is a configurable integer, thereference size can be configured per serving cell, or per configurednumerology of a serving cell, per configured BWP of a serving cell. Insome embodiments, the reference size is equal to the size of a commonCORESET in the scheduled serving cell (i.e. the serving cell in which orin a BWP of which the multicast PDSCH/PUSCH is allocated to betransmitted). In some embodiments, the reference size is equal to thesize of the CORESET with CORESET ID #0 in the scheduled serving cell. Insome embodiments, the reference size is equal to the size of the initialDL BWP or the initial UL BWP of the scheduled serving cell. In someembodiments, the reference size is equal to the size of DL BWP (or ULBWP) configured in the scheduled serving cell which has the smallest BWPID or largest BWP ID among the DL BWPs (or UL BWPs) configured in thescheduled serving cell for a UE. In some embodiments, the reference sizeis equal to the size of the default DL BWP (or UL BWP) in the scheduledserving cell.

In some embodiments, the resource allocation field may be used toidentify the RBs allocated for a multicast PDSCH/PUSCH based on anassigned sub-band, where a sub-band is a set of contiguous RBs within aserving cell which is associated to multicast communication. In someembodiment, RB numbering for multicast resource allocation starts fromthe lowest RB of the assigned sub-band. The assigned sub-band may be apriori information to a UE or a group of UEs for multicastcommunication. In some embodiments, the assigned sub-band for multicasttransmission is configured using higher layer signaling, e.g. as part ofBWP configuration. In some embodiments, a serving cell is divided into aset of sub-bands and the assigned sub-band for multicast transmission isselected from the set of sub-bands. In one example, CRBs of a servingcell are divided into sub-bands of the same size, herein called sub-bandsize. In one embodiment, the assigned sub-band for multicasttransmission is a sub-band (from the set of sub-bands of the scheduledserving cell) which is fully contained in the scheduled BWP and has thelowest sub-band index within the set of sub-bands of the scheduledserving cell. In one embodiment, the assigned sub-band for multicasttransmission is indicated to a UE from the set of sub-bands of thescheduled serving cell via a higher layer signaling e.g., a radioresource communications (RRC) signaling, or via a MAC CE signaling orvia a DCI message, or a combination thereof. In some embodiments, asubset of the set of sub-bands of the scheduled serving cell is firstactivated using MAC CE or higher layer signaling and a DCI message isthen used to indicate the assigned sub-band for multicast transmissionfrom the activated subset of the set of sub-bands of the scheduledserving cell. The DCI message used to indicate the assigned sub-band formulticast transmission may be the same DCI massage that is used forscheduling the multicast PDSCH/PUSCH, in which case a separate DCIbitfield in the DCI message may be used for such indication.

In some embodiments where the CRBs of a serving cell are divided intosub-bands of the same size (sub-band size), the sub-band size may eitherbe a priori information to a UE or a group of UEs for multicastcommunication or otherwise communicated via higher layer signaling,e.g., RRC signaling, or via MAC CE signaling, or via a DCI message, or acombination thereof. The DCI message that is used for indication of thesub-band size may be the same DCI massage that is used for schedulingthe multicast PDSCH/PUSCH. In some embodiments, the sub-band size isequal to the size N_(size) that is used to determine the size of themulticast resource allocation field. In some embodiments, the sub-bandsize is either a fixed number or a predefined number or a numberconfigured by higher layers. In embodiments where the sub-band size is aconfigured by higher layers, the sub-band size can be configured perserving cell, or per configured numerology of a serving cell, perconfigured BWP of a serving cell. In some embodiments, the sub-band sizeis equal to the size of a common CORESET in the scheduled serving cell(i.e. the serving cell in which or in a BWP of which the multicastPDSCH/PUSCH is allocated to be transmitted). In some embodiments, thesub-band size is equal to the size of the CORESET with CORESET ID #0 inthe scheduled serving cell. In some embodiments, the sub-band size isequal to the size of an initial DL BWP or an initial UL BWP of thescheduled serving cell. In some embodiments, the sub-band size is equalto the size of DL BWP (or UL BWP) configured in the scheduled servingcell which has the smallest BWP ID or largest BWP ID among the DL BWPs(or UL BWPs) configured in the scheduled serving cell for a UE. In someembodiments, the sub-band size is equal to the size of the default DLBWP (or UL BWP) in the scheduled serving cell. In some embodiments, thegranularity of the sub-band size is either of one PRB, or one PRG, orone RBG, or one RB bundle, or a higher layer configurable integer numberof PRBs.

FIGS. 4A-4D are diagrams of multicast resource allocation schemes401-403 for signaling multicast resource allocations to UEs 222, 224.Similar to the BWPs 332, 334 in FIGS. 3A-3C, the BWPs 432, 434 arescheduled to the UEs 222, 224 (respectively), and may be on the samecomponent carrier (or serving cell) or on different component carriers(or serving cells). As shown, the BWP 432 at least partially overlapswith the BWP 434 in the frequency domain such that a common sequence ofcontiguous RBs (RB₀, RB₂, . . . , RB₈) belong to both of the BWPs 432,434.

In each of the multicast resource allocation schemes 401-404 showing inFIG. 4A to 4 d, the base station 210 sends a resource allocation field481-484 to the UEs 222, 224. Similar to the resource allocation fields381-383 in FIGS. 3A-3C, the resource allocation fields 481-483 indicatea starting RB index and an RB range (implicitly using RIV orexplicitly), and are used to identify a set of contiguous RBs allocatedfor the multicast PDSCH/PUSCH. However, the starting RB index indicatedby (or derived from the RIV indicated by) the resource allocation fields481-483 is used to identify the starting RB of the set of contiguous RBsallocated for the multicast PDSCH/PUSCH based on the lowest RB of thesub-band 480. Here the lowest RB of the sub-band refers to the startingRB of the sub-band, or equivalently, an RB which has the smallest CRBindex in the sub-band. The RB range indicated by (or derived from theRIV indicated by) the respective resource allocation fields 481-483 isthen used to identify the ending RB of the set of contiguous RBsallocated for the multicast PDSCH/PUSCH based on the identified startingRB of the set of contiguous RBs allocated for the multicast PDSCH/PUSCH.In some embodiments, the set of contiguous RBs is a set of contiguousVRBs, wherein the starting RB is a starting VRB and the RB range is aVRB range. Similar to the resource allocation field 384 in FIG. 3D, theresource allocation field 484 indicates a bitmap of RBGs, and is used toidentify a set of RBs allocated for the multicast PDSCH/PUSCH. Similarto FIG. 3D, in the example of FIG. 4D, the RBG size is equal to 2, i.e.each RBG (except for the first RBG in this example) consists of 2 RBs.The first RBG includes reference RB 490. The second RBG includes RBs 491and 492. The third RBG includes RBs 493 and 494. The fourth RBG includesRBs 495 and 496. The fifth RBG includes RBs 497 and 498. It should beappreciated that the RBG size can be any other integer value P. In someembodiments, the RBG size can be a power of 2. In some embodiments, theRBG size may be a fixed value, or a predefined value, or a valueconfigured by higher layers, e.g. as part of BWP configuration. Itshould be noted that the first RBG (which includes the reference RB)and/or the last RBG may have a partial size, i.e. they may consist ofless than P RBs. This is because RBG boundaries may or may not bealigned with the reference RB.

Denote by M the reference size for multicast transmission or sub-bandsize for multicast transmission or the size of the scheduled multicastBWP (according to any of the corresponding embodiments in thisdisclosure). In some embodiments, if the size N_(size) (which is usedfor determination of the size of the resource allocation field) isdifferent from M, for resource allocation type 1, a UE first obtains astarting RB index and an RB range from the resource allocation field(e.g. derives a starting RB index and an RB range from the RIV fieldusing N_(size) is the size of the BWP), and then scales the obtainedstarting RB index and RB range by a factor of max(M/N_(size), 1) roundeddown to the nearest power of 2, and then uses the scaled starting RBindex and RB range to identify a set of contiguous RBs allocated for themulticast PDSCH/PUSCH based on the reference RB for multicasttransmission within the scheduled BWP or based on an assigned sub-bandfor multicast transmission within the scheduled BWP or based on thescheduled multicast BWP (according to any of the correspondingembodiments in this disclosure In some embodiments, the set ofcontiguous RBs is a set of contiguous VRBs, wherein the starting RB is astarting VRB and the RB range is a VRB range.

Combing the above 3A to 3D and the FIGS. 4A to 4D, FIG. 5 is a flowchartof a method 500 for multicast service as may be performed by a basestation. At step 510, the base station transmits a resource allocationfield indicating a starting RB index and an RB range to allocate a setof contiguous RBs for a multicast PDSCH/PUSCH to a group of UEs. Thegroup of UEs can be scheduled with different BWPs or in acarrier-aggregation. At step 520, the base station transmits or receivesdata from the group of UEs over the set of contiguous RBs allocated forthe multicast PDSCH/PUSCH to or from UEs in the group of UEs. In someembodiments, the set of contiguous RBs is a set of contiguous VRBs,wherein the starting RB is a starting VRB and the RB range is a VRBrange. The resource allocation field can be any one of the above detailsshowing in 3A to 3D and the FIGS. 4A to 4D.

Combing the above 3A to 3D and the FIGS. 4A to 4D, FIG. 6 is a flowchartof a method 600 for multicast service performed by a UE in a group ofUEs configured for multicast transmission/reception. At step 610, the UEreceives a resource allocation field indicating a starting RB index andan RB range from a base station. At step 620, the UE identifies a set ofcontiguous RBs allocated for a multicast PDSCH/PUSCH based on thestarting RB index and the RB range indicated by the resource allocationfield. At step 630, the UE transmits or receives multicast data to orfrom the base station over the set of contiguous RBs allocated for themulticast PDSCH/PUSCH in one BWP or group-common BWP. Before the step610, the UE obtains a reference RB for identifying the set of contiguousRBs (not shown). The reference RB can be predefined or signaling to theUE and the set of contiguous RBs allocated for multicast PDSCH or PUSCHare used for multiple UEs transmitting data to the base station at asame time slot or different time slot. In some embodiments, the set ofcontiguous RBs is a set of contiguous VRBs, wherein the starting RB is astarting VRB and the RB range is a VRB range.

In some embodiments, a multicast DCI message is used to identify amulticast BWP (or group-common BWP) and to identify a set of RBsallocated for a multicast PDSCH/PUSCH within the identified multicastBWP. In some embodiments, RB numbering for multicast resource allocationstarts from the lowest RB of the identified multicast BWP. When morethan one multicast BWP are configured to a UE or a group of UEs, a BWPID may be included in the multicast DCI to identify the scheduledmulticast BWP among all BWPs configured to a UE or among the multicastBWPs configured to the UE. When only a single multicast BWP isconfigured to a UE or a group of UEs, the multicast DCI message mayidentify the scheduled multicast BWP without including a BWP ID. Themulticast DCI includes a resource allocation field which indicates a setof RBs allocated for a multicast PDSCH/PUSCH within the scheduledmulticast BWP. The resource allocation field may indicate a starting RBindex and an RB range (implicitly using an RIV or explicitly), which areused to identify a set of contiguous RBs allocated for the multicastPDSCH/PUSCH within the scheduled multicast BWP. In some embodiments, theset of contiguous RBs is a set of contiguous VRBs, wherein the startingRB is a starting VRB and the RB range is a VRB range. Alternatively, theresource allocation field may use a bitmap to indicate a set of RBGs,which are used to identify the RBs allocated for the multicastPDSCH/PUSCH within the scheduled multicast BWP. FIG. 7 is a diagram of amulticast resource allocation scheme 700 for signaling a multicast DCImessage 781, to UEs 222, 224, 226 for scheduling the multicast BWP 720.As shown, the DCI message 781 is communicated within the BWPs 711, 712,713 which are the active BWPs of UEs 222, 224, 226 respectively, and isused to identify the scheduled multicast BWP 720 and to indicate a setof RBs allocated for a multicast PDSCH/PUSCH within the scheduledmulticast BWP 720.

FIG. 8 is a flowchart of a method 800 for multicast service as may beperformed by a base station. At step 810, the base station transmits amulticast DCI message identifying a multicast BWP and at least one RBallocated for multicast data transmission/reception. In this example,the multicast DCI message excludes a BWP ID. At step 820, the basestation transmits or receives multicast data over the at least one RB inthe multicast BWP to or from UEs in the group of UEs.

FIG. 9 is a flowchart of a method 900 for multicast service performed bya UE in a group of UEs configured for multicast transmission/reception.At step 910, the UE receives a multicast DCI message identifying amulticast BWP and at least one RB allocated for multicast datatransmission/reception within the identified multicast BWP, where themulticast DCI message excludes a BWP ID. At step 920, the UE identifiesthe multicast BWP based on the multicast DCI message. At step 930, theUE transmits or receives multicast data over the at least one RB in themulticast BWP to or from UEs in the group of UEs.

FIG. 10 is a block diagram of an embodiment processing system 1000 forperforming methods described herein, which may be installed in a hostdevice. As shown, the processing system 1000 includes a processor 1004,a memory 1006, and interfaces 1010-1014, which may (or may not) bearranged as shown in FIG. 10. The processor 1004 may be any component orcollection of components adapted to perform computations and/or otherprocessing related tasks, and the memory 1006 may be any component orcollection of components adapted to store programming and/orinstructions for execution by the processor 1004. In an embodiment, thememory 1006 includes a non-transitory computer readable medium. Theinterfaces 1010, 1012, 1014 may be any component or collection ofcomponents that allow the processing system woo to communicate withother devices/components and/or a user. For example, one or more of theinterfaces 1010, 1012, 1014 may be adapted to communicate data, control,or management messages from the processor 1004 to applications installedon the host device and/or a remote device. As another example, one ormore of the interfaces 1010, 1012, 1014 may be adapted to allow a useror user device (e.g., personal computer (PC), etc.) tointeract/communicate with the processing system 1000. The processingsystem 1000 may include additional components not depicted in FIG. 10,such as long term storage (e.g., non-volatile memory, etc.).

In some embodiments, the processing system 1000 is included in a networkdevice that is accessing, or part otherwise of, a telecommunicationsnetwork. In one example, the processing system 1000 is in a network-sidedevice in a wireless or wireline telecommunications network, such as abase station, a relay station, a scheduler, a controller, a gateway, arouter, an applications server, or any other device in thetelecommunications network. In other embodiments, the processing system1000 is in a user-side device accessing a wireless or wirelinetelecommunications network, such as a mobile station, a user equipment(UE), a personal computer (PC), a tablet, a wearable communicationsdevice (e.g., a smartwatch, etc.), or any other device adapted to accessa telecommunications network.

In some embodiments, one or more of the interfaces 1010, 1012, 1014connects the processing system 1000 to a transceiver adapted to transmitand receive signaling over the telecommunications network. FIG. 11 is ablock diagram of a transceiver 1100 adapted to transmit and receivesignaling over a telecommunications network. The transceiver 1100 may beinstalled in a host device. As shown, the transceiver 1100 comprises anetwork-side interface 1102, a coupler 1104, a transmitter 1106, areceiver 1108, a signal processor 1110, and a device-side interface1112. The network-side interface 1102 may include any component orcollection of components adapted to transmit or receive signaling over awireless or wireline telecommunications network. The coupler 1104 mayinclude any component or collection of components adapted to facilitatebi-directional communication over the network-side interface 1102. Thetransmitter 1106 may include any component or collection of components(e.g., up-converter, power amplifier, etc.) adapted to convert abaseband signal into a modulated carrier signal suitable fortransmission over the network-side interface 1102. The receiver 1108 mayinclude any component or collection of components (e.g., down-converter,low noise amplifier, etc.) adapted to convert a carrier signal receivedover the network-side interface 1102 into a baseband signal. The signalprocessor 1110 may include any component or collection of componentsadapted to convert a baseband signal into a data signal suitable forcommunication over the device-side interface(s) 1112, or vice-versa. Thedevice-side interface(s) 1112 may include any component or collection ofcomponents adapted to communicate data-signals between the signalprocessor 1110 and components within the host device (e.g., theprocessing system 1000, local area network (LAN) ports, etc.).

The transceiver 1100 may transmit and receive signaling over any type ofcommunications medium. In some embodiments, the transceiver 1100transmits and receives signaling over a wireless medium. For example,the transceiver 1100 may be a wireless transceiver adapted tocommunicate in accordance with a wireless telecommunications protocol,such as a cellular protocol (e.g., long-term evolution (LTE), etc.), awireless local area network (WLAN) protocol (e.g., Wi-Fi, etc.), or anyother type of wireless protocol (e.g., Bluetooth, near fieldcommunication (NFC), etc.). In such embodiments, the network-sideinterface 1102 comprises one or more antenna/radiating elements. Forexample, the network-side interface 1102 may include a single antenna,multiple separate antennas, or a multi-antenna array configured formulti-layer communication, e.g., single input multiple output (SIMO),multiple input single output (MISO), multiple input multiple output(MIMO), etc. In other embodiments, the transceiver 1100 transmits andreceives signaling over a wireline medium, e.g., twisted-pair cable,coaxial cable, optical fiber, etc. Specific processing systems and/ortransceivers may utilize all of the components shown, or only a subsetof the components, and levels of integration may vary from device todevice.

It should be appreciated that one or more steps of the embodimentmethods provided herein may be performed by corresponding units ormodules. For example, a signal may be transmitted by a transmitting unitor a transmitting module. A signal may be received by a receiving unitor a receiving module. A signal may be processed by a processing unit ora processing module. Other steps may be performed by an identifyingunit/module and/or a determining unit/module. The respectiveunits/modules may be hardware, software, or a combination thereof. Forinstance, one or more of the units/modules may be an integrated circuit,such as field programmable gate arrays (FPGAs) or application-specificintegrated circuits (ASICs).

Although this invention has been described with reference toillustrative embodiments, this description is not intended to beconstrued in a limiting sense. Various modifications and combinations ofthe illustrative embodiments, as well as other embodiments of theinvention, will be apparent to persons skilled in the art upon referenceto the description. It is therefore intended that the appended claimsencompass any such modifications or embodiments.

What is claimed is:
 1. A method for a multicast service, the methodcomprising: receiving, by a user equipment (UE), a control formatincluding a resource allocation field from a base station (BS), theresource allocation field indicating a starting resource block (RB)index and an RB range; obtaining a set of RBs allocated for a multicastphysical downlink shared channel (PDSCH) or physical uplink sharedchannel (PUSCH) based on a starting RB location and the RB range;wherein the starting RB location is associated with the stating RB indexand at least one of a reference RB location or an assigned sub-band; andtransmitting or receiving, by the UE, data over at least one RB of theset of RBs allocated for the multicast PDSCH or PUSCH.
 2. The method ofclaim 1, wherein obtaining the set of RBs of the multicast PDSCH orPUSCH comprises: locating a starting RB of the multicast PDSCH or PUSCHbased on the starting RB location and the reference RB location; andlocating an ending RB of the multicast PDSCH or PUSCH based on the RBrange and the starting RB of the multicast PDSCH or PUSCH.
 3. The methodof claim 1, wherein the obtaining the set of RBs of the multicast PDSCHor PUSCH comprises: locating a starting RB of the multicast PDSCH orPUSCH based on the starting RB location and a starting RB of theassigned sub-band; and locating an ending RB of the multicast PDSCH orPUSCH based on the RB range and the starting RB of the multicast PDSCHor PUSCH.
 4. A method for a multicast service, the method comprising:sending, by a base station (BS), a resource allocation field to a groupof UEs, the resource allocation field indicating a starting resourceblock (RB) index and an RB range; and transmitting or receiving, by thebase station (BS), data over at least one RB of a set of RBs of amulticast PDSCH or PUSCH with the group of UEs, wherein the set of RBsof the multicast PDSCH or PUSCH is identified based on a starting RBlocation and the RB range, and the starting RB location is associatedwith the stating RB index and at least one of a reference RB location oran assigned sub-band.
 5. The method of claim 4, the method furthercomprising: assigning, by the BS, a multicast group identity (ID) to afirst UE and a second UE of the of group UEs, constructing, by the BS, acontrol format which includes the resource allocation field, and aCyclic Redundancy Check (CRC) based on the control format, andscrambling, by the BS, the CRC by the multicast group ID.
 6. The methodof claim 4, wherein the reference RB is assigned to the group of UEs bya higher layer signaling, and the reference RB comprises a firstplurality of reference RBs comprising a set of common RBs, the set ofcommon RBs configured by higher layers.
 7. The method of claim 6, themethod further comprising: sending, by the BS, a BWP identifier (ID)indicating a first BWP to a first UE and a second BWP to a second UE,and wherein the at least one RB belongs to one of the first BWP and thesecond BWP.
 8. The method of claim 7, wherein the at least one RBbelonging to the one of the first BWP and the second BWP has a lowest RBindex among a first subset of the first plurality of reference RBs, thefirst subset of the first plurality of reference RBs belonging to thefirst BWP.
 9. The method of claim 4, wherein the set of RBs of themulticast PDSCH or PUSCH is further identified based on one of: a sizeof an initial downlink bandwidth part (BWP) or an initial uplink BWPconfigured for a component carrier; a size of a downlink BWP or anuplink BWP, the downlink BWP or uplink BWP having a smallest BWP IDamong a plurality of downlink BWPs or uplink BWPs configured for a firstUE within the component carrier; a size of a default downlink bandwidthpart (BWP) or a default uplink BWP configured for the component carrier;a size in accordance with which a size of the resource allocation fieldis determined; or a size which is configured using a higher layersignaling message.
 10. A device comprising: a non-transitory memorystorage comprising instructions; and one or more processors incommunication with the non-transitory memory storage, wherein the one ormore processors execute the instructions to: receive a control formatincluding a resource allocation field from a base station (BS), theresource allocation field indicating a starting resource block (RB)index and an RB range; obtain a set of RBs allocated for a multicastphysical downlink shared channel (PDSCH) or physical uplink sharedchannel (PUSCH) based on a starting RB location and the RB range;wherein the starting RB location is associated with the stating RB indexand at least one of a reference RB location or an assigned sub-band; andtransmit or receive data over at least one RB of the set of RBsallocated for the multicast PDSCH or PUSCH.
 11. The device of claim 10,wherein the instructions to obtain the set of RBs comprise instructionsto: locate a starting RB of the multicast PDSCH or PUSCH based on thestarting RB location and the reference RB location; and locate an endingRB of the multicast PDSCH or PUSCH based on the RB range and thestarting RB of the multicast PDSCH or PUSCH.
 12. The device of claim 10,wherein the instructions to obtain the set of RBs comprise instructionsto: locate a starting RB of the multicast PDSCH or PUSCH based on thestarting RB location and a starting RB of the assigned sub-band; andlocate an ending RB of the multicast PDSCH or PUSCH based on the RBrange and the starting RB of the multicast PDSCH or PUSCH.
 13. A devicecomprising: a non-transitory memory storage comprising instructions; andone or more processors in communication with the non-transitory memorystorage, wherein the one or more processors execute the instructions to:send a resource allocation field to a group of UEs, the resourceallocation field indicating a starting resource block (RB) index and anRB range; and transmit or receive data over at least one RB of a set ofRBs of a multicast PDSCH or PUSCH with the group of UEs, wherein the setof RBs of the multicast PDSCH or PUSCH are identified based on astarting RB location and the RB range, and the starting RB location isassociated with the stating RB index and at least one of a reference RBlocation or an assigned sub-band.
 14. The device of claim 13, whereinthe one or more processors execute further instructions to: assign amulticast group identity (ID) to a first UE and a second UE of the groupof UEs, construct a control format which includes the resourceallocation field, and a Cyclic Redundancy Check (CRC) based on thecontrol format, and scramble the CRC by the multicast group ID.
 15. Thedevice of claim 13, wherein the reference RB is assigned to the group ofUEs by a higher layer signaling, and the reference RB comprises a firstplurality of reference RBs comprising a set of common RBs, the set ofcommon RBs configured by higher layers.
 16. The device of claim 15,wherein the one or more processors execute further instructions to senda first BWP identifier (ID) indicating a first BWP to a first UE and asecond BWP to a second UE, and wherein the at least one RB belongs toone of the first BWP and the second BWP.
 17. The device of claim 16,wherein the at least one RB belonging to the one of the first BWP andthe second BWP has a lowest RB index among a first subset of the firstplurality of reference RBs, the first subset of the first plurality ofreference RBs belonging to the first BWP.
 18. The device of claim 13,wherein the set of RBs of the multicast PDSCH or PUSCH is furtheridentified based on one of: a size of an initial downlink bandwidth part(BWP) or an initial uplink BWP configured for a component carrier; asize of a downlink BWP or an uplink BWP, the downlink BWP or uplink BWPhaving a smallest BWP ID among a plurality of downlink BWPs or uplinkBWPs configured for a first UE within the component carrier; a size of adefault downlink bandwidth part (BWP) or a default uplink BWP configuredfor the component carrier; a size in accordance with which a size of theresource allocation field is determined; or a size which is configuredusing a higher layer signaling message.